Description

We revisited the problem of the existence of plasmonic modes guided by metal-dielectric-metal slot waveguides. For the case of lossless slot waveguides, we classify the guided modes in the structure with the metal dispersion and found that, in a certain parameter range, three different guided modes coexist at a fixed frequency, two (symmetric and antisymmetric) forward propagating modes and the third, backward propagating antisymmetric mode. We study the properties of the forward and backward...[Show more] plasmonic guided modes in the presence of realistic losses, and discuss the importance of evanescent modes in lossy structures.